Nipple invagination is a pathological phenomenon in which the nipple does not protrude from the surface of the areola or is even sunken, like a crater. The incidence of nipple invagination in women is about 1 to 2%. The incidence of nipple invagination in women is about 1 to 2%. It often occurs on both sides, but can also be seen on one side only, and the degree of nipple invagination on both sides may not be the same. The nipples are deep in the areola, which is not only unsightly, but also because the sunken nipples can accumulate dirt or oil, causing itching, eczema or inflammation. Severe invagination makes it difficult for the baby to suckle milk. This causes inconvenience and psychological depression to the patient. The degree of nipple invagination varies from person to person. In mild cases, the nipple is only receding to varying degrees and can be squeezed out by hand or protruded from the body by negative pressure sucking. In severe cases, the nipple is completely submerged on the surface of the areola and cannot be extruded, often growing in reverse. Of course these invaginated nipples are generally smaller even when extruded. There is often no visible nipple neck. The depth of nipple invagination varies and can be divided into three categories: one is partial nipple invagination, the nipple neck exists and can be easily extruded, and the size of the nipple after extrusion is similar to normal; the second category, the nipple is completely submerged in the areola, but the nipple can be squeezed out by hand, the nipple is smaller than normal, and most do not have a nipple neck; the third category is the nipple is completely buried under the areola, and it is impossible to make the invaginated nipple extrude. The general causes of nipple invagination are skin and subcutaneous tissue subsidence, nipple smooth muscle dysplasia, breast duct shortening, and partial tissue fibrosis contracture. The main causes of severe nipple invagination are ductal shortening and tissue fibrosis contracture. Most of the clinical observations of nipple invagination are primary nipple deformities. The main causes of primary nipple invagination are: poorly developed smooth muscle in the nipple and areola: the nipple has an opening for the milk duct, smooth muscle fibers around the milk duct, and the invaginated nipple is pulled inward by bundles of muscle fibers surrounding the milk duct and inserted into the dermis of the nipple. The texture of these muscle bundles differs significantly from that of the milk ducts. Hypoplasia of the milk ducts themselves: Hypoplastic milk ducts fail to ductalize and appear as striae. Lack of support tissue under the nipple is also a cause of nipple invagination. The main causes of secondary nipple invagination: secondary nipple invagination (acquired nipple invagination) deformity is less common and is caused by the nipple being pulled by pathological tissue in the breast or by unreasonable corseting or wearing too tight a bra. The disease is caused by inflammation, tumor and other diseases that invade the ducts, ligaments and fascia of the breast, causing contraction of the invaded ducts, ligaments and fascia; unreasonable corseting or wearing too tight bra occurs in adolescence, due to tight chest, poor blood circulation, resulting in poor breast development and congenital nipple invagination. In acquired nipple invagination, the infection factor is one of the main factors of nipple invagination, mainly mammary ductitis with fibrosis scar contracture affects its normal development and causes nipple invagination. The significance of this nipple deformity is different in the presence of nipple invagination in malignant tumors of the breast. In women with previously normal breasts, if nipple invagination occurs for no apparent reason, mammography and other examinations should be performed to help diagnose such cases of nipple invagination. Hazards: It can easily cause diseases such as nipple areola inflammation and mastitis; affect breastfeeding; affect the health of the baby and the postpartum recovery of the mother; affect the beauty of the breast; affect sexual life; affect the psychological health of the patient. Treatment: Mild cases can be corrected by manipulation and pulling, while severe cases require surgery or correction with a stent. Surgery can leave surgical scars, damage the milk ducts, and have a high rate of long-term recurrence after surgery. The stent method does not require surgery and does not leave a scar, only two wires are inserted under local anesthesia and the stent is implanted, which is less painful and faster to recover. In conclusion, nipple invagination can affect the physical and mental health of female patients, and the stent method of nipple invagination correction brings a boon to patients with nipple invagination.